In a course, I made a collaborative Wiki with no groups. My students say they cannot see the content of the wiki pages I have made. I don't mind if students edit the pages, but they can't see (from their accounts) what I have put there for them.

What do I need to adjust to allow students to see this wiki? Where is the 'site managing setting'?

As was said earlier on in this thread, you shouldn't have to change anything in the site settings because if the wiki is in a course the students should by default be able to see and edit the pages. Are the students in groups in the course -even though you have made the wiki with no groups? Can you post some screenshots of how you have set up the pages they can't see and what it looks like from the students' viewpoint?

I instructed my students to just hit the edit button. One told me that there was no edit button. If I sign in as a student, this is what I see.

I can see edit as a teacher or non-editing teacher. I have spent over an hour going into every setting in Moodle regarding wikis and roles at the site level. Everything is set, as far as I can see, to allow students to edit wikis by default.

We are experiencing the same problem in at least one wiki in at least one course in Moodle 2.3.1. Your solution does not seem to make a difference. It concerns a collaborative wiki, separate groups and of course groups do exist in the course. Teachers and admins are able to edit normally. It is puzzling.

UPDATE: It seems to be caused by the "Force format" setting. I had HTML selected as format and force format on. When I turned force format off the wiki became editable, although users have to select the format for every page.

In our Moodle 2.3.1 turning Force format on in a collaborative wiki with groups the students cannot edit the wiki or see the pages. In a collaborative wiki with no goups there is no problem with the Force format setting. In collaborative wikis with the group modes separate or visible groups, Force format must not be selected or else the students cannot edit. The tracker issue is MDL-33491.